Ignition device



Sept. 11, 1945. E. OLSON ETAL IGNITION DEVICE Filed NOV. 30, 1944 Z'Zmr 01,70): dzapZg M Z/Jdle INVENTOR.

BY W

Patented Sept. 11, 1945 IGNITION DEVICE Elmer Olson, Ferndale, and Stanley M. Udale, Detroit, Mich., assignors to George M. Holley and Earl Holley Application November 30, 1944, Serial No. 565,892 4 Claims. (01. 123-117) The object of this invention is to improve the promptness in response to suction used to advance the ignition in proportion to the air flow through a venturi and also with the suction in the inlet manifold. The negative response to a reduction in suction is also important, and here also instantaneous response is desirable.

It has previously been proposed to have two separate diaphragms, one responsive to the manifold and one responsive to the Venturi suction.

It has also been suggested to have a diaphragm simultaneously responsive to both the Venturi suction and the manifold suction, and it has also been proposed to have a diaphragm responsive to manifold suction as modified by the Venturl suction, and when the manifold suction became low as the throttle approached wide open for an automatic, spring-loaded check valve to eliminate the manifold suction. The difliculty is that the response is not instantaneous and knocking occurs during the transition period, which is fatal to commercial success. One difliculty is that more suction is available at part throttle than can usefully be employed.

Figure 1 shows diagrammatically the application of one form of our invention to the ordinary ignition system and carburetor in general use on automobiles.

Figure 2 shows an alternative construction.

Figure 3 shows another design.

In Figure 1, I is' an air entrance, II is a venturi, I2 is a fuel nozzle discharging therein. 13 is a mixture outlet, I4 is a throttle valve therein, IE is a relatively unrestricted passage con-' meeting the throat of the venturi l I with a chamber IS. in which is located a double-ended valve IT. This double-ended valve l1 seats on the two ends of a perforated sleeve l8, which is perforated by openings l9, which provide free communication from the passage l5 to the chamber 16.

A passage 20, adjacent to and on the atmospheric side of the upstream lip of the throttle I4 (when throttle is in its idling position), communicates with a chamber 2 I, in which is located a compression spring 22, which causes the lower end of the valve H to seat on the lower seat of the sleeve l8; a pipe 23 connects the chamber IS with a chamber 24, in which is located a spring 25 and a diaphragm 26. The diaphragm 2G responds to suction and rotates a circuitbreaker plate 21 anti-clockwise, thereby advancing the spark, the limit of the advance and retardation being determined by the stops 48-49.

2311s a storage battery, 30 is a standard high 33 to engage with the rotating cam 34.

In Figure 2, the double-ended flat valve 31 takes the place of the double-ball valve l1 (Figure 1) and the spring 22 has been eliminated. .The passage 38 leads from the throat of the venturi II to the chamber 35 below the valve 31, which is so constructed that it has only a limited lift. The chamber 4| above the valve 31 is in communication with the engine suction the moment the throttle l4 opens so that the pipe 23 transmits the engine suction the moment the throttle l 4 opens.

The restrictions 45 and 44 are selected so that the suction in 24 does not exceed 'by many inches of mercury the maximum suction attained in the throat ll of the venturi. The circuit breaker plate 21 is advanced against the stop at wide open throttle maximum speed. In certain cases (passenger cars), a greater part throttle advance is required, say 40% more, than wide open advance.

. In the latter case, the part throttle suction will be approximately 40% greater than wide open throttle venturi suction at maximum speed.

In Figure 3, the valve 42 is given only a limited lift and covers the passage 43, which communicates through a restriction with the throat of the venturi ll. Here the restriction 46 in the outlet of passage 43 into venturi I I is larger than the restriction 41, which admits engine suction to lift the valve 42.

Operation In Figure 1, when the throttle I4 is partially open, the moment the engine fires, the upper seat of the valve l1 engages with the upper seat of the sleeve 18 and thus a high suction is transmitted to the chamber 24. and the spark is advanced to the maximum desirable spark advance. When the throttle is opened suddenly, the valve I1 is pushed up by the sprin 22 and seats on the bottom of the sleeve l8. Immediately, there is a wide open passage from 23 through passages l9 past the valve I! through the passage l5 to the venturi II. In other words, the pressure in chamber 24 immediately falls almost to atmospheric pressure, and the spark is suddenly and completely retarded.

Now the criticism that has been directed against all ignition devices of the type in which the centrifugal governor weights have been removed is that they perform perfectly with one defect, and that is there is an annoying sequence of knocks following the acceleration of the car. This annoying sequence of knocks induces the owner to retard the spark and thereby loss of mileage that he would otherwise secure. The result is that although this type of ignition control (eliminating the centrifugal weights) has been advocated for 20 years, the centrifugal device with all its difliculties has been universally used. This advantage, therefore, although slight, is commercially of considerable importance. The unrestricted pipe 23, unrestricted passage l5, the large openings I9 in the sleeve 18 and the unrestricted passage 20 constitute the novel means required to get the desired improvements; the valve I! is the element that makes the device commercially possible.

In Figure 2, the double-ended valve 31 is raised the moment the valve I4 opens away from the idling position so that its upper surface is subjected to the engine suction. Otherwise, the action of valve 31 is very similar to the action of valve l1. However, part throttle suction is approximately 20" Hg as compared with 5 /2 to 7" maximum Venturi suction, so that in all cases more part throttle suction is available than can be usefully employed in advancing the spark. Hence, the suction at 45 is reduced by the vent 44. Hence, the opening 44 would be somewhat larger than 45.

In Figure 3, a single-flat valve is used, sealed by gravity. Being thin, its weight is very small so that the slightest suction causes it to lift. However, the outlet from the passage 43 to the venturi II is necessarily restricted. This is objectionable, as the vacuum trapped in chamber 24 cannot instantaneously relieve itself as is the case with the constructions shown in Figures 1 and 2, which are the preferred constructions.

In Figure 3, the suction in the Venturi throat, which advances the spark when the throttle is wide open, is as great as or almost as great as the part throttle suction transmitted through the restriction 41, because the restriction 46 is greater than the restriction 41.

What we claim is:

1. A spark advance device for an automotive engine comprising a carburetor having an air entrance, a venturi therein, a first unrestricted passage communicating with the throat of said venturi, a throttle located downstream of said venturi, an air chamber, a moving wall therein, spring means controlling the movement of said moving wall, an ignition timing device connected to said moving wall, a second unrestricted passage connecting the chamber with the first unrestricted passage, a double-ended valve located at the junction of the two passages, automatic means for moving said double-ended valve to a position which places the two passages in unrestricted communication with each other when the engine is not in operation, a second air chamber located adjacent said valve, a passage located with reference to said throttle so as to connect said second chamber with the air entrance on the atmospheric side of said throttle when said throttle is in its idling position and with the engine side of said throttle immediately after the throttle is moved away from its idling position, means responsive to the engine suction and to the initial opening of the throttle with reference to said passage so as to move said valve against said yieldable means by the application of the engine suction to said valve, said valve being adapted to simultaneously close the unrestricted passage leading to the Venturi and to connect the second unrestricted passage with the engine side of the throttle through said second chamber whereby when the throttle is opened wide, the double-ended valve seats and the first unrestricted passage is again placed in unrestricted communication with the second unrestricted passage, and the vacuum created in said chamber escapes rapidly through said unrestricted passages.

2. A device as set forth in claim 1 in which the second air chamber has a first opening of restricted area communicating with the atmosphere and a second opening of restricted area larger than the first opening, said second opening being in the passage connecting said second chamber with the engine side of said throttle immediately after the throttle is moved away from its idling position.

3. A spark advance device for an automotive engine comprisin a carburetor having an air entrance, a venturi, a first unrestricted passage communicating with the throat of said venturi, a throttle located downstream of said venturi, an air chamber, a moving wall therein, spring means controlling the movement of said moving wall, an ignition timing device connected to said moving wall, a second unrestricted passage connecting the chamber with the first unrestricted passage, a double-ended valve located at the junction of the two passages, said valve being adapted to seat by gravity in a position which places the two passages in unrestricted communication with each other when the engine is not in operation, a second air chamber located adjacent said valve, a passage located with reference to said throttle so as to connect said second chamber with the air entrance on .the atmospheric side of said throttle when said throttle is in its idling position and with the engine side of said throttle immediately after .the throttle is moved away from its idling position, means responsive to the engine suction and to the initial opening of the throttle with reference to said passage for moving said valve against the force of gravity by the application of the engine suction to said valve, said valve being adapted to simultaneously close the unrestricted passage leading to the Venturi and to connect the second unrestricted passage with the engine side of the throttle through said second chamber whereby when -.the throttle is opened wide, the doubleended valve seats and the first unrestricted passage is again placed in unrestricted communication with, the second unrestricted passage, and the vacuum created in said chamber escapes rapidly through said unrestricted passages.

4. A device as set forth in claim 3 in which the second air chamber has a first opening of restricted area communicating with the atmosphere and a second opening of restricted area larger than the first opening, said second opening being in th passage connecting said second chamber with the engine side of said throttle immediately after the throttle is moved away from its idling position.

EIMER OLSON.

STANLEY M. UDALE. 

